rusty sword; sword with a rusted edge; useless sword
Rare term for a sword whose blade has rusted, rendering it useless. Can be used literally or figuratively for something that has lost its effectiveness.
古い蔵から錆刀が出てきた。
A rusty sword was found in the old storehouse.
彼の腕前も今や錆刀のようなものだ。
His skill is now like a rusty sword—useless.
Compound of 錆 (さび, 'rust') and 刀 (かたな, 'sword'), with rendaku voicing of かたな to がたな. The word is rare and likely a straightforward descriptive compound.